A Li2O—Al2O3—SiO2 based crystallized glass contains, as a main crystal, a β-quartz solid solution (Li2O.Al2O3.nSiO2 [n ≧2]) or a β-spodumene solid solution (Li2O.Al2O3.nSiO2 [n≧4]), and hence, it has such characteristic that expansion is extremely low and that mechanical strength is high. Therefore, the Li2O—Al2O3—SiO2 based crystallized glass has excellent thermal characteristics. In addition, since a crystal to be precipitated can be changed by changing a heat treatment condition in a crystallization step, both a transparent crystallized glass in which a β-quartz solid solution precipitates and a white opaque crystallized glass in which a β-spodumene solid solution precipitates can be produced from a mother glass (crystallizable glass) of the same composition and used for different purposes according to an application.
Making use of such characteristics, the Li2O—Al2O3—SiO2 based crystallized glass previously has been used for various applications; such as front windows of oil stoves, wood stoves, and the like, substrates for high-technology products such as color filter substrates, image sensor substrates, substrates for top plates of electromagnetic cookers, gas cookers, and the like, window glasses for fire-retarding doors, base materials for reflecting mirrors to be used for projectors such as liquid crystal projectors, or light source lamps for illumination, setters for heat treatment of electronic components or plasma display panels, trays for microwave ovens, and electronic components or precision machine components.